To pass through each room, pick up a keycard then exit through the door on top.
Use w,a,s,d or arrow keys to move your player.
Use mouse to aim, left click to shoot / hold down for continuous fire / Switch weapons with #1, #2 and #3 keys
If the game slows down on your PC, you can press P key to switch to low quality mode. It should speed things up with only text looking worse, the rest should still look fine